Fluoroformal and fluorthioformal compounds and production thereof



United States Patent 3,328,453 FLUOROFORMAL AND FLUORTHIOFORNIALCOMPOUND AND PRODUCTION THEREOF Karl 0. Christe and Attila E. Pavlath,Berkeley, Calif., assignors to Stauffer Chemical Company, New York,N.Y., a corporation of Delaware No Drawing. Filed Aug. 7, 1963, Ser. No.300,657 9 Claims. (Cl. 260-455) This invention relates to a new andnovel method for preparing fluorine containing aromatic compounds. Thenature of the aromatic nucleus may be monocyclic or polycyclic and maybe either unsubstituted or in addition to the fluoroformyl orfluorothiolforrnyl groups it may have such groups present as halogen,alkyl, haloalkyl, alkoxy, haloalkoxy and the like. In particular, itrefers to a new process for preparing the novel classes of fluorinatedaromatic compounds, aromatic fluoroformates and aromaticfluorothiolformates, and to new species of these classes such asphenylfiuoroformate, phenylfluorothiolformate, p-phenylenebisfluoroformate, p-tolylfluoroformate, l-naphthylfiuoroformate,s-phenenyltrisfiuoroformate, and the like.

The arylchloroformates, which are well known, have been describedfrequently in the literature. Especially, the preparation and chemicalproperties of phenylchloroformate have been studied and described in theliterature. The arylfluoroformates heretofore were unknown except forphenylfluoroformate. But the novel properties of these compounds permitstheir use in a variety of applications. For example, they can be used asintermediates in preparing the corresponding fluoro aromatic compoundsas shown in our co-pending application Ser. No. 454,215 filed May 7,1965, now US. Patent No. 3,283,- 018 which is a continuation-in-partapplication of Ser. No. 300,666 filed on even date herewith, nowabandoned, as intermediates for organic compounds useful in agriculturalchemicals, pharmaceuticals, as plasticizers, and in resins. In general,according to US. Patent No. 3,283,018, by a process of thermaldecomposition of arylfluoroformates or arylfiuorothiolformates undersubstantially anhydrous conditions at temperatures between about 350 C.and 900 C., the corresponding nuclearly fluorinated aromatic compoundsmay be prepared.

The arylchloroformates, especially phenylchloroformate, have beenprepared and their properties studied. There are three general methodsfor the preparation of phenylchloroformate described, all of whichdiffer sufficiently from the present invention to deem it novel. Theonly reported preparation of phenylfluoroformate was by Emeleus andWood, J. Chem. Soc. 1948, 2183-8. In this paper phenylfluoroformate wasdescribed and its preparation was carried out by reacting carbonylfluoride with phenol in an autoclave. The yield of phenylfiuoroformatewas not very high because of excessive diphenylcarbonate formation inthe procedure used.

The methods for the preparation of phenylchloroformate andphenylfiuoroformate are not uniformly applicable for preparing thearylfiuoroformates of this invention. The methods of the prior art arefrequently difficult to control as to the desired product andarylcarbonate formation is the resulting undesirable product.

The above information is equally applicable to phenylchlorothiolformate,except that phenylfluorothiolformate is not mentioned in the literature.But it can be stated that diaryldithiolcarbonate would be the undesiredbyproduct formed in any analogous reaction.

A general object of the present invention is, therefore, to provide anew process for preparing arylfluoroformates andarylfluorothiolformates.

A more specific object is a process for the preparation of suchfluoro'formates and fluorothiolformates in high yield and with a minimumof carbonate and dithiolcarbonate formation.

Pursuant to the above mentioned and yet further objects, it has beenfound that aromatic fluoroformates and aromatic fiuorothiolformates canbe conveniently prepared by reacting carbonyl chlorofluoride with anaromatic compound containing any number of hydroxyl groups or thiolgroups, respectively, bonded directly to the aromatic carbon atoms orthe sodium or potassium salt of an aromatic hydroxyl-containingcompound. The arenol or arenthiol may be further substituted with suchgroups as halogen, alkyl, haloalkyl, alkoxy, haloalkoxy and the like.

Actually, the reaction can be carried out under many varying conditions.However, the conversion of the arenols and the arenthiols and the yieldsof the corresponding aromatic fluoroformate were maximized to nearlytheoretical values, which is unusual for this typ of reaction.

By arenols and arenthiols we mean all hydroxy and thiol containingaromatic compounds in which the hydroxy and thiol groups are linkeddirectly to an aromatic carbon atom.

The reaction is carried out under substantially anhydrous conditions tominimize hydrolysis of the desired fluoroformates andfiuorothiolformates. The vessels used for the reaction should be ofsubstantial material as will allow operation at high pressures andmoderate temperatures. Provision should be made to remove excesscarbonyl chlorofluoride after the reaction is completed. Some form ofagitation of the reactants is desirable in order to achieve a moreintimate contact. The products of the reaction can be separated byconventional methods of vacuum distillation in the case of liquids, andcrystallization in the case of solids.

Carbonyl chlorofluoride, which here is used as a reactant, can lbCprepared by several methods described in the literature (Emeleus andWood, J. Chem. Soc. 1948, 2183-8).

The reaction will proceed at atmospheric and superatmospheric pressures.However, the preferred pressure is superatmospheric. An excess ofcarbonyl chlorofiuoride is used to help shift the equilibriumestablished in the reactor to the desired products and decreasecarbonate formation.

The proportion of carbonyl chlorofiuoride to arenol or arenthiol is notnarrowly critical. The preferred range of reactants is at least 1 molcarbonyl chlorofluoride for each hydroxyl or thiol equivalent present inthe aromatic compound. The particularly preferred range is 1 to 2 molcarbonyl chlorofiuoride for each hydroxyl or thiol equivalent present inthe aromatic compound. An excess of carbonyl chlorofluoride, as statedabove, is desirable to decrease the amount of carbonate ordithiolcarbonate formation. The use of an inert solvent, preferablytoluone or benzene, was found necessary to increase the yield ofarylfluoroformate and likewise decrease carbonate formation.

The purity of the carbonyl chlorofluoride is not critical under thepreferred conditions. Carbonyl chlorofluoride containing up to 15%impurities of carbonyl fluoride and carbonyl chloride did not show amarked decrease in arylfluoroformate produced. No chloroforrnates orcarbonate formation was detected which indicates that carbonylchlorofiuoride has a superior reactivity over these two impuritycomponents.

The reaction will proceed with or without a catalyst, although the useof a basic catalyst was found useful in obtaining maximum conversionsand yields. In general, any saturated tertiary amine may be used as acatalyst. The preferred tertiary amine for our reactions was tri-n- 3butylamine. Good results are obtained when using between 1%' and 20%catalyst by weight, based on the weight of the arenol or arenthiol used.

The temperature of the reaction is not critical and is kept as low .asoperability permits. Preferably, the tem- 4' Example 9 A 150 ml.stainless steel reaction bottle was charged with 0.1 mol thiophenol in50 ml. of benzene, and 0.5 ml. of tri-n-butylarnine was used as acatalyst. Carbonyl I chlorofluoride (0.2 mol) was condensed in thevessel.

of a

ditions of this invention Each ar enol and arenthiol will heated to 500whlle being sham-an on a shakmg table have its conditions as temperatureressure and At the end of 12 hours the conversion of the starting ma- 1terial thiophenol was 100% and the yield of phenylfluoroaction time, butwill lie Within the limits of this inventhiolformate was 100% 23; gg themaxlmum temperature need not The phenylfiuorothiolformate was purifiedby vacuum The sodium or otassium salt of the arenol or arendlstinafion'It dlstiued at 3 at 9 thiol ma be substi iuted for the free arenol orarenthi l The demented analysls was: 53"85% theoretical although theconversion of these compounds to the est: 53'59% found;.H 322%theoretical 339% found; responding arylfluoroformate andarylfluorothiolformate 15 51% theoietlcgl 2042% found The compmind was ais not as acceptable as that obtained when the free arenol colorlesshquld Wlth a pungent odor other physlcal properties, refractive index1.5273 at 24 C. and density 1.223 or arenthiol is used. at 24 a d p g 20singlet at -43.6 p.p.m. (CFCl internal standard) and prose 1 1 forprotons the usual aromatic absorption at.455 p.p.m. Examp es (TMSinternal standard). Infrared investigation produced An autoclave wascharged with 0.1 mol phenol in 50 the expected vibrations for thephenylfiuorothiolformate. ml. of toluene and, when a basic catalyst wasused, 0.5 Exam le 10 ml. tri-n-butylamine. The carbonyl chlorofluoride,0.2 25 p mol, was then condensed in the autoclave. The autoclave In thesame manner as the above examples, hydroquiwas shaken to agitate thereactants. The following table none was treated with carbonylchlorofluoride in an autoshows the experimental detail and results. Thetempera clave at 60 C. in toluene as a solvent and using 5% triture wasmeasured by an external thermocouple. Toluene n-butylamine as acatalyst. The autoclave was shaken was used as the solvent in all of theexamples in Table I. for 15 hours and an autogenous pressure of 250p.s.i.

TABLE I Percent Percent Yields Example Catalyst Temp. Time PressureConver- Plienyl Diphenyl (deg) (his) (atm.) sion of fluorocarbonatePhenol formats 1 12 i 2.3 100 2... Noam) 40 12 i 6.2 100 3- 70 i2 1 23.4100 4. s0 12 1 10.2 100 5. so 12 19.1 77.1 54. 3 e. 35 12 15 24. 2 100 7N(1But) so 12 20.4 97.2 99.4

The. reaction mixture in each case was worked up by developed. Theproduct was recrystallized from hexane, removal of the solvent first.Then the impure product after removal of the solvent in vacuo. wasvacuum distilled to obtain the purified phenylfluoro- The conversion ofhydroquinone was 99.9% and the formate. The phenylfluoroformate had aboiling point yield of p-phenylene-bis-fluoroformate was 99.9%. Reof47.1" C. at 7 mm. Hg. The elemental analysis was crystallization yieldeda white crystalline compound with close to the theoretical values. Otherphysical properties, a melting point of 6768 C. The molecular weight wasrefractive index 1.4642 at 265 C. and density 1.201 at found to be 208as compared to the theoretical 202. 23.8 C. Nuclear magnetic resonanceand infrared investigations The infrared spectra of phenylfluoroformateand the were used to confirm the expected structure. phenylchloroformatewere run. A comparison showed the theoretically expected shift of the(:0 vibration in the Example 11 i 12 b1 fluorine compound to higherfrequencies and addition h procedure of Example 1S equally app e to C-Fvibration and the elimination of the C-Cl vibram'dlhydroxy benzeneo'dlhydroxylblenzem' tion. The F nuclear magnetic resonance spectrum ofthe Same .mannel at to 90 a 45% We d of any product showed one singletat 16.5 p.p.m. (CCl F as the 'h i was Obtamed' The Converslon 0 internalstandard), which we have found to be the exstarimg {natenal was The spected absorption region for the fluorine in this class Punfied m vacuoand exhlblteq a pomt4o 67 of Compounds C. at 1 mm. Hg. The refractiveindex was 1. 563 at Example 8 22 C. and density 1.412 at 23 C.

The analysis: C, theory 47.5%, found 47.7%; H, theo- In a similarprocedure as the examples above, sodium- 5 W 1.98%, found 229%, and F,theory 189% found phenolate (0.1 mol) and carbonyl chlorofluoride (0.213,7% mol) were reacted. The reaction was run in toluene as a Th .bif til th Compound was h t more Solvent A Pressure of autogellous Pressure,difiicult to prepare, since the formation of the intramowas developed inthe shaking autoclave. The autoclave was 1e 1 carbonate f o d B varyingh di i heated to 50 C. for 12 hours. 70 and reactants used it waspossible to reach a maximum The conversion of Sodium phenolate Was 135%,the yield of ortho phenylene-bis-fluoroforrnate at 47.7. The yield ofphenylfluoroformate was 100%.The reaction mix t f abl temperature was 20C using i h i. ture was worked up by distillation in vacuo. Thephenylamine as a catalyst fluoroformate was characterized in the mannerdSCI1b6d The o{tho-p]1enylene-bis-fluorgfgrmate was a colorless inExamples 1-7. lachrymatory liquid with a boiling point of 77 C. at

7 mm. Hg. Nuclear magnetic resonance and infrared analysis confirmed theexpected compound.

Example 13 In the same manner as the previous examples,p-trifiuoromethylphenol and carbonyl chlorofluoride were reacted intoluene with 5% tri-n-butylamine as a catalyst. The conversion of thestarting material was 99.0% and the yield of p-CF C H OCOF was 100%.

The properties are B.P. 68 C. at 25 mm. Hg, refractive index 1.4151 at255 C. and density 1.390 at 24 C.

Analysis for the compound: Calculated, 46.16% C, 36.55% F, 1.82% H;Found, 46.21% C, 36.6% F, 1.96% H. Infnared analysis presented theexpected spectrum. Investigation by F nuclear magnetic resonance showedan absorption, a singlet, at +16.8 p.p.m. typical for the OCOF group anda singlet at +63.7 p.p.m. typical for the -CF group (CFCl used as aninternal standard).

Example 14 Following a similar procedure as outlined in the aboveexamples, the reaction was carried out between p-bromophenol andcarbonyl chlorofluoride in toluene as a solvent with a small amount oftri-n-butylamine catalyst. Conversion of the starting material was 100%;yield of p-'Br-C H4OCOF was 99.9%.

The compound can be characterized by the following properties: colorlessliquid, B.P. 72.5 at 6 mm. Hg, refractive index 15170 at 238 0., density1.657 at 24 C.

Analysis.Theory, 38.36% C, 1.83% H, 8.68% F, 36.53% Br; Found, 38.47% C,1.97% H, 8.80% F, 36.80% Br. The compound was further characterized byits infrared and nuclear magnetic resonance spectra.

Example 15 According to the procedure of the previous examples,p-methoxyphenol and carbonyl chlorofluoride were reacted to preparep-methoxyphenylenefiuoroforrnate.

Properties: colorless liquid, B.P. 51 C. at 1 mm. Hg, refractive index1.4843 at 23 C., density 1.252 at 24 C.

Analysis-Theory, 56.47% C, 4.12% H, 11.18% F. Found: 57.34% C, 4.14% H,11.3% F.

Example 16 According to the procedure of the previous examples,p-methylphenol and carbonyl chlorofluoride were reacted to preparep-rnethylphenylenefiuoroformate.

Properties: colorless liquid, B.P. 70 C. at 1 mm. Hg, refractive index1.4663 at 24 C., density 1.143 at 248 C Analysim-Theory, 62.34% C, 4.55%H, 12.34% F. Found: 62.32% C, 4.51% H, 11.8% F.

Example 17 According to the procedure of the previous examples,a-naphthol and carbonyl chlorofluoride were reacted to prepareu-naphthylfluoroformate.

Properties: colorless liquid, B.P. 80 C. at 1 mm. Hg, refractive index1.5662 at 24 C., density 1.251 at 24.5 C

Analysis.-'Iheory, 69.47% C, 3.68% H, 10.00% F. Found: 69.36% C, 3.67%H, 9.7% F.

Example 18 6 Example 19 According to the procedure of the previousexamples, o-bromophenol and carbonyl chlorofluoride were reacted toprepare o-bromophenylenefiuoroformate.

Properties: colorless, disagreeable smelling liquid, B.P. 66 C. at 4.55mm. Hg. Refractive index 1.5110 at 22 C., density 1.610 at 23.5 C.

Analysis.Theory, 38.36% C., 1.83% H, 36.53% Br, 8.68% F. Found: 38.62%C, 1.92% H, 36.96% Br, 7.8% F.

Example 20 According to the procedure of the previous examples,o-lluorophenol and carbonyl chlorofluoride were reacted to prepareo-fiuorophenylenefiuoroformate.

Properties: colorless liquid, B.P. 3334 C. at 6.55 mm. Hg. Refractiveindex 1.4434 at 23 C., density 1.275 at 24 C.

Analysia-Theory, 52.83% C, 3.14% H, 23.90% F. Found: 53.45% C, 2.96% H,23.8% F.

Example 21 According to the procedure of the previous examples,1,3,5-trihydroxybenzene and carbonyl chlorofluoride were reacted toproduce 1,3,S-phenenyl-trisfluoroformate.

Properties: white crystalline compound, M.P. 92 C. Analysis.Theory,40.91% C, 1.14% H, 21.59% F. Found: 41.23% C, 1.37% H, 21.50% F.

Various changes and modifications may be made in the process describedherein as will be apparent to those skilled in the chemical arts. It isaccordingly intended that the present invention only be limited by thescope of the appended claims.

We claim:

. The compound, phenylfluorothiolforrnate.

. The compound, p-phenylene bis-fluoroformate.

. The compound, p-bromophenylfluoroformate.

. The compound, 1,3,5-phenenyltrisfiuoroformate.

. The compound, a-naphthylfiuoroformate.

A process for producing substituted aromatic compounds selected from thegroup consisting of phenyl and naphthyl compounds having at least onesubstituent selected from the group consisting of fluoroformyl (OCOF)and fluorothiofor-myl (SCOF) comprising contacting carbonylchlorofluoride with a substituted aromatic compound selected from thegroup phenyl and naphthyl having at least one substituent selected fromthe group consisting of hydroxyl, thiol, and the alkali metal salsthereof at a temperature range of about 0 C. to- 15 C.

7. The process defined in claim 6, wherein the reaction is carried outat superatmospheric pressure.

8. The process defined in claim 6 wherein the reaction is carried out inthe presence of a saturated tertiary amine.

9. The process defined in claim 6 wherein the reaction is carried out atsuperatmospheric pressure in the presence of a saturated tertiary amine.

References Cited UNITED STATES PATENTS 2,351,366 6/1944 Pohl et a1.260-455 2,721,208 '10/1955 Losee et al. 260-463 OTHER REFERENCES Emeleuset al.: Chemical Society Journal (London) (1948), part III, pp.2183-2188.

Yarovenkeno et al.: Chemical Abstracts 1960, vol. 54,

DALE MAHANAND, DELBERT R. PHILLIPS,

Assistant Examiners.

1. THE COMPOUND, PHENYFLUOROTHIOFORMATE.
 6. A PROCESS FOR PRODUCINGSUBSTITUTED AROMATIC COMPOUNDS SELECTED FROM THE GROUP CONSISTING OFPHENYL AND NAPHTHYL COMPOUNDS HAVING AT LEAST ONE SUBSTITUENT SELECTEDFROM THE GROUP CONSISTING OF FLUOROFORMUL (-OCOF) AND FLURORTHIOFORMYL(-SCOF) COMPRISING CONTACTNG CARBONYL CHLOROFLUORIDE WITH A SUBSTITUTEDAROMATIC COMPOUND SELECTED FROM THE GROUP PHENYLAND NAPTHYL HAVING ATLEAST ONE SUBSTITUENT SELECTED FROM THE GROUP CONSISING OF HYDROXYL,THIOL, AND THE ALKALI METAL SALTS THEREOF AT A TEMPERATURE RANGE OFABOUT 0*C. TO 150*C.